Broadcast studios are often required to deliver two or more audio streams associated with an audio and/or video program. For example, the primary audio stream may include the primary dialogue, music, and effects for a program, and a secondary audio stream may include descriptive audio, e.g., speech intended for visually impaired audiences.
An audio stream may or may not be active at all times. For example, the secondary audio stream, including the descriptive audio, may be active during periods of setting up and describing a scene (or a scene change) in a program. However, if the secondary audio stream is active at the same time as the primary audio stream, the secondary audio stream may not be intelligible to a user over the primary audio stream.
The approaches described in this section are approaches that could be pursued, but not necessarily approaches that have been previously conceived or pursued. Therefore, unless otherwise indicated, it should not be assumed that any of the approaches described in this section qualify as prior art merely by virtue of their inclusion in this section. Similarly, issues identified with respect to one or more approaches should not assume to have been recognized in any prior art on the basis of this section, unless otherwise indicated.